usb: PS3 EHCI QH read work-around
authorGeoff Levand <geoff@infradead.org>
Wed, 9 Nov 2011 00:01:18 +0000 (16:01 -0800)
committerBen Hutchings <ben@decadent.org.uk>
Tue, 19 Jun 2012 22:18:27 +0000 (23:18 +0100)
commit5f081af6cbb83e72194ad3a82623ca42eeb0e662
tree9f15f8452856bf80f45eab0df08b0d00e1687308
parent29623c3e8dd0a0b94f2f3ee6ccb08345acff2b1e
usb: PS3 EHCI QH read work-around

commit aaa0ef289afe9186f81e2340114ea413eef0492a upstream.

PS3 EHCI HC errata fix 244.  The SCC EHCI HC will not correctly perform QH
reads that occur near or span a micro-frame boundry.  This is due to a problem
in the Nak Count Reload Control logic (EHCI Specification 1.0 Section 4.9.1).

The work-around for this problem is for the HC driver to set I=1 (inactive) for
QHs with H=1 (list head).

Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drivers/usb/host/ehci-hcd.c